A young woman is framed for the murder of a wealthy man who met his death at the hands of his heirs.

Suave private investigator Norman Conquest intercepts a secret message and meets a beautiful but foreign blonde lady in room 605 of the Park Plaza hotel. But when Conquest wakes up in the room the next morning he is lying next to a dead body. With the mysterious blonde nowhere to be seen, Conquest soon becomes the police s number one suspect with Inspector Williams following his every move. In order to clear his name, Conquest enlists the help of Pixie Everard (Joy Shelton), but the going gets rough when he discovers that the murder is connected to a stash of stolen diamonds. As gun-happy gangs of communists and Nazi sympathizers turn up the heat, Conquest has to solve the murder whilst staying one step ahead of both the gangs and the police.

A man is accused of a series of murders that were actually committed by a crazed killer called "The Tiger." He must prove his innocence and catch the murderer.

In 1880, the criminal called The Wolf is responsible for a murderous rampage in France. When the Brisson Bank is robbed in Paris and the employee Michelle is murdered, the wealthy Chevalier Lucio del Gardo is the only chance to save the bank. Chevalier proposes to the owner M. de Brisson to deposit a large amount of gold, but in return he would like to marry his daughter Cecile. However, Cecile is in love with the efficient clerk Lucien Cortier that belongs to the lower classes and refuses the engagement. In order to get rid off the rival, Chevalier uses evidences to incriminate Lucien, manipulating the incompetent Parisian chief of police.